Cam shaft lapping machine



May 8, 1934; H. J. WILLS CAM SHAFT LAPPING MACHINE Filed March 3, 193Q 2 She9t s$heet 1 ,Zfivenwr HERBERT J. WILLS ATTORNEY May 8, 1934. H. J. WILLS CAM SHAFT LAPPING MACHINE Filed Mafch s, 1930 2 Sheets-Sheet 2 fiver 2%?" HERBERT J. wu L.s

ATTORNEY Patented May {8, 1934 1,957,568 can snare memo mom Herbert J. Willis, Niagara Falls, N.Y.,'asslgnor to The Carbon-madam @ompany, Niagara Falls,

N. Y., a corporation of Pennsylvania Application March 3, 1930, Serial No. 432,881

4. Claims.

My invention relates to means for lapping of parts associated with a cam shaft. By means of my improved device it is possible to lap all the cams or cam hearings on a given shaft simultaneously. It is also possible with my improved apparatus to lap any of the cams or com bearings individually or in any desired combination.

My improved lappin apparatus is illustrated by the accompanying drawings in which:

Figure 1 is a plan view of my cam shaft lapping mechanism;

Figure 2 is a side elevation of the same;

Figure 3 is a section of the line III-Ill of Figure 2; I

Figure 4 is an end view of one of 'my lapping heads;

Figure 5 gives a sectional view of the lapping head on the line VV of Figure 4 and shows the method of support of the lapping head on its driving shaft;

Figure 6 is a cross-section of a countershadt taken on the line VI- VE of 2;

Figure 7 is a section of a gear and shaft taken on the line VII-Vllof Fig. l; and

Figure 8 is a section of a gear and shaft on the line VIE-VIII of Fig. 2.

Referring to the drawings in more detail a; heavy base 9 supports a head stool; and a tail stool;

which carry a cam shaft 2. The base may also contain an electric motorwhich is used to drive a belt l'l. The latter drives a shaft by means of a pulley 22; The shaft 15 carries a driving disl: 19. The can: shaft 7 is pivotally supported for rotation on centers carried by theheacl steer and tail stool: respectively, the cam shaft being removable and insertible on adjustment of the tail stool: center by means of the hand wheel 12 which is threaded in the standard 11. A slot in the driving disk 19 is used to turn the dog 13 which is connected rigidly to the cam shaft 7 when it isdesired to turn the latter during the lapping operation. Speed-reducing means not shown may be used to drive the belt 17 and hence the cam shaft 7 at a slow rate of speed during the lapping operation.

The means for driving the specific lapping mechanism disclosed in the present application will now be described. A spur gear 16 is keyed to the shaft 15 and meshes on either side with smaller gears 18 and 18" which are keyed re-' on the opposite side of the cam shaft. The coun- Therefore the description of thetershaft 2 is rotatably supportedin a member 21 which is rigidly attached to the base 9. A collar 31 is keyed on the shaft 2 in such a position that the hub of the gear 18 and the collar 31 prevent substantial longitudinal movement of the countershaft 2. The axis of this countershaft is parallel to the axis of rotation of the cam shaft 7. A series of spiral gears 3 are provided with keys which are adapted to slide in a groove in the shaft 2. This groove extends along the shaft 2 for a distance substantially equal to the length of the cam shaft under treatment and to the end of the shaft which is adjacent to the tail stock. See Figures 8 and 8 for the key 30 which is rigid with the gear 3 but is slidable in the groove in the shaft 2. The gear 3 can be moved along the shaft 2 by moving the carriage i l which is mounted on tracks on the case 9 so that the carriage can be moved parallel to the axis of rotation of the worlr piece. A similar standard is provided for each spiral gear 3. Each standard carries bearings 25 for the shaft 2. The gear 3 is confined between these bearings. The standard 14 also carries bearings for a lapping shaft 5 which is rotated by means of a spiral gear 4, whichgear is mounted so that it meshes with the spiral gear 3 and rotates about an axis perpendicular to the axis of rotation of 3. The gear 4 is confined between the bearings 32 (see Fig. 3). A short key 29 is rigid with the gear 4 and fits loosely-in a groove in the shaft 5. The

- gear 4 is slidably mounted therefore on the shaft 5, but the shaft 5 is compelled to turn with the gear. The lapping shaft 5 is provided with a rigid- 1y attached lapping head 6. The shaft 5 has a collar 33 keyed to it. This collar carries a bearing for one end of a spring 23 which surrounds the shaft 5. The other end of the spring 23 abuts an end bearing 34 which in turn abuts the standard is as shown in Fig. 3. The spring 23 is effective in keeping the lapping head 6 pressed against the cam or hearing which is being lapped. The lapping head 6 is rotated while finely divided abrasive 27 is supplied from a source of supply 26. The lapping head 6 may be made of wood, steel, iron or non-ferrous materials. The lapping head 6 may also be made of bonded abrasive in which case the supply of abrasive 27 from the source 26 may a be partly or wholly dispensed with. Owing to the relative sizes of the gears 16 and 18, the lapping head 6 is driven at a higher speed than the cam shaft under treatment.

As shown in Figure 2, standards 14, 14" each carrying its full equipment of lapping machinery are mounted on opposite sides of thecam shaft. The standard 14 and its equipment are simply representative of a number of similar standards (carrying corresponding equipment) which are mounted on the same side of the cam shaft. A similar statement holds for standards 14" on the opposite side of the cam shaft. It is not intended that the lapping cylinders or disks 6, 6 on opposite sides of the cam shaft should act on the same cam. It is desirable from considerations of the space occupied by the standards 14 that the lapping units on one side of the cam shaft should be used on alternate surfaces to be lapped and not on the same surface. After the units carried by standards 14 on one side of the cam shaft have been arranged to lap every second surface, the units carried by standards 14" on the opposite side of the cam shaft are placed in position to lap the intermediate surfaces.

To recapitulate, in the mode of operation the lapping of the cam and bearings is accomplished by the rapid rotation of the terminal surfaces of the lapping cylinders or disks 6, 6" with the aid of suitable abrasive material which may be externally supplied from time to time as indicated at 26 and 27 in Fig. 3, or which may be embedded in the surface of the lapping cylinder or disk. The driving connections for one of the cylindrical ends 6 include as shown in Figures 1 and 2 the belt 17, pulley 22, shaft 15, gear 16, gear 18, shaft 2, spiral gear 3, spiral gear 4, shaft 5 and finally the lapping cylinder or disk 6.

My lapping apparatus may be used with cam shafts of various lengths by varying the position of the tail stock pivot. Clamping means 28 may be provided for clamping the standards 14 in any desired position on the base 9.

The lapping cylinders or disks 6 are self-dressing since the entire force exerted by a given cylinder 6 is brought into active abrasion against a cam or bearing. The working surfaces of the cylinders or disks 6 may be made independently renewable.

I claim:

1. A lapping machine for cam shafts and the like comprising a base, a rotatable head stock and a longitudinally adjustable tail stock for supporting and rotating a cam shaft during the lapping operation, a main driving shaft keyed to said head stock, a large spur gear keyed to said driving shaft, a countershaft mounted parallel to the driving shaft,,a relatively small spur gear keyed to said countershaft and in mesh with said large spur gear, a support for a lapping head adjustably mounted on said base so that it may be moved parallel to said countershaft, a spiral gear slidably mounted on said countershaft to rotate therewith and to transmit power to said lapping head, a third shaft for rotating said lapping head while the latter is pressed against a rotating surface to be lapped, said shaft being mounted to rotate in said adjustably mounted support, a spiral gear mounted to rotate with said last mentioned shaft and to drive the same, said spiral gear being driven by the countershaft spiral gear, a lapping head mounted for rotation on an end of said last mentioned shaft adjacent to a surface to be lapped and mounted for reciprocation with respect to said surface, and resilient means acting on the lapping head to press the latter against a surface to be lapped.

2. The lapping machine described in claim 1 in which there is a countershaft and a. plurality of adjustable supports mounted on either side of said cam shaft, each adjustable support carrying lapping mechanism driven by engagement between a spiral gear mounted on one of the countershafts and an engaging spiral gear mounted on the corresponding adjustable support, whereby cams and cam bearings can be lapped simultaneously on both sides.

3. A lapping machine for lapping separately or simultaneously a plurality of cam shaft surfaces comprising in combination a base, a head stock and a tail stock for supporting the cam shaft for rotation about its axis, tracks extending along said base on either side of the work piece and parallel to its axis of rotation, standards which are slidable on one or more of said tracks so that they may be positioned opposite the surfaces to be lapped, a lapping head slidably mounted in a rotatable member on each standard, resilient means, for pressing each of said lapping heads against the adjacent surface to be lapped, a driving shaft on each side of the cam shaft for transmitting power to all the lapping heads on the same side of the cam shaft, and a pair of intermeshing spiral gears for each transmission from a driving shaft to a lapping head, finely divided abrasive being supplied from time to time to each lapping surface.

4. Apparatus for lapping a plurality of cam shaft surfaces simultaneously and on both sides of the cam shaft axis comprising a rotatable head stock and an adjustable tail stock, a track disposed on each side of a line joining the centers of the head stock and of the tail stock and running parallel to said axial line, a plurality of similar standardsslidably mounted on each track, a driving shaft for rotating the head stock and for also rotating a cam shaft clamped in the head stock and rotatably supported at its opposite end on the tail stock, a countershaft disposed on each side of the head stock for rotation about an axis which is parallel to the axis of rotation of the cam shaft, a plurality of spiral gears slidably mounted on each countershaft and driven thereby, a secondary spiral gear mounted for rotation on each standard about an axis perpendicular to the axis of rotation of the cam shaft, and a lapping head driven by each of said secondary spiral gears and resiliently pressed against a surface to be lapped.

HERBERT J. WILLS. 

